Basal NO locally modulates human iliac artery function in vivo

We demonstrated previously that endogenous NO influences large-artery distensibility in the ovine hindlimb. However, the role of basal NO in larger human conduit arteries is controversial. The aim of this study was to investigate whether basal production of NO, acting locally, influences iliac artery distensibility in humans. Distensibility was assessed by intra-arterial measurement of the pulse wave velocity. Eighteen subjects, free of significant coronary or iliac artery disease, were studied after diagnostic cardiac catheterization. Simultaneous pressure waveforms were recorded with a high-fidelity dual-pressure sensing catheter, placed in the common iliac artery during intra-arterial infusion of saline (baseline), glyceryl trinitrate (4 nmol/min), or NG-monomethyl-L-arginine (8 and 16 micromol/min). Drugs were infused proximally, via the catheter to perfuse the segment of artery under study, or distally, via the sheath, to control for any reflex changes in flow or sympathetic activation. Velocity was calculated using the foot-to-foot methodology. Six subjects received glyceryl trinitrate and 12 NG-monomethyl-L-arginine. There was no change in velocity after infusion of glyceryl trinitrate or NG-monomethyl-L-arginine via the sheath. However, infusion of glyceryl trinitrate via the catheter significantly reduced velocity by 31.43+/-5.80% (mean+/-SEM; P<0.01; P=0.02 for comparison). Likewise, infusion of the highest dose of NG-monomethyl-L-arginine via the catheter significantly increased velocity by 27.25+/-8.20% (P=0.001; P=0.02 for comparison). Importantly, there was no change in mean arterial blood pressure throughout the studies. These data indicate that under resting conditions, local NO production modulates human iliac artery distensibility and that exogenous NO increases arterial distensibility.     

Progesterone modulates the expression of HDL binding sites in human skin fibroblasts

The aim of this work was to study the effects of progesterone on the expression of high density lipoprotein binding sites by cultured human skin fibroblasts. At concentrations ranging between 10(-6)- and 10(-4) M the hormone showed a dose-dependent induction of the HDL binding sites. The effect was maximal at 48 h. The increased HDL binding was only due to an up-regulation of binding sites, without changes of the apparent Kd. This effect was not related to changes of cellular cholesterol content, and was not affected by inhibition of protein synthesis. These data suggest that the expression of binding sites for HDL can be modulated via a mechanism that does not depend upon cellular cholesterol content.     

HDL composition and HDL antioxidant capacity in patients on regular haemodialysis

Recent evidence suggests that HDL can directly inhibit LDL oxidation, a key early stage in atherogenesis. Patients with chronic renal failure are at increased cardiovascular risk, have reduced HDL levels and altered HDL composition. We have therefore investigated whether compositional changes in HDL lead to decreased HDL antioxidant capacity in these patients. In comparison to control subject HDL, patient HDL contained less total cholesterol, cholesterol esters, phospholipids and alpha-tocopherol. LDL, HDL and LDL + HDL were standardised for protein and oxidised in the presence of Cu2+. The rate of propagation during HDL oxidation was reduced in the patient group (3.28+/-0.65 x 10(-5) vs. 4.60+/-0.97 x 10(-5) abs. U/min, P < 0.01). Lipid peroxide generation in patient HDL was decreased: 6.56+4.4 versus 13.42+/-7.0 nmol malondialdehyde (MDA)/mg HDL protein after 90 min and 14.45+/-3.8 versus 20.11+/-7.8 nmol MDA/mg HDL protein after 180 min. This is attributable to reduced HDL polyunsaturated fatty acid content in patients (0.53+/-0.12 vs. 0.72+/-0.16 mmol/g HDL, P < 0.01). The inhibitory effect of HDL on LDL oxidation was similar: 71 and 33% for patient HDL compared to 68 and 31% for control HDL, after 90 and 180 min, respectively. Compositional changes of HDL in patients on haemodialysis did not affect the antioxidant capacity of HDL after standardisation for HDL protein. However, reduced HDL levels in vivo may result in reduced HDL antioxidant capacity in these patients.     

Development of Novel Therapeutics to Raise HDL and Block Inflammation

Plant derived phospholipids are rich in linoleic acid (LA) and have therapeutic value to treat inflammatory diseases of the liver,intestine and vasculature. These phospholipids act to normalize plasma lipid levels and prevent atherosclerotic disease. Oral administration of LA-phospholipids to cholesterol-fed rabbits prevents the development of atherosclerosis.     

糖尿病和冠心病患者高密度脂蛋白结构与其抗炎作用的相关性研究

目的比较2型糖尿病和冠心病患者与健康人高密度脂蛋白(HDL)对内皮细胞表达粘附分子的抑制能力,并研究其与HDL中血清淀粉样蛋白A(SAA)含量改变的相关性。方法通过密度梯度离心法从健康人、单纯糖尿病患者、糖尿病合并冠心病患者以及单纯冠心病患者血浆样本中提取HDL,用酶联免疫吸附法检测HDL中SAA及载脂蛋白AⅠ(apo AⅠ)含量。将健康人及不同患者的HDL与脐静脉内皮细胞(HUVEC)共同孵育,通过肿瘤坏死因子α刺激,分别与抗人CD54-PE、CD106-FITC单克隆抗体及Calcein-AM荧光染色剂标记后的THP-1细胞共同孵育后,流式细胞术检测平均荧光强度获得HUVEC细胞间粘附分子1(ICAM-1)、血管细胞粘附分子1(VCAM-1)表达数量及THP-1细胞粘附数量,从而比较不同组别HDL抑制粘附分子表达及抑制细胞粘附的能力。结果健康人群HDL中SAA含量与单纯糖尿病及单纯冠心病患者HDL中SAA含量相比均明显降低[(4.89±1.46)ng/μg比(22.54±7.40)ng/μg及(13.28±5.05)ng/μg,均为P<0.05]。健康对照组及各疾病组HDL均可使HUVEC表达ICAM-1、VCAM-1水平明显下降,其中健康对照组HDL抑制ICAM-1表达能力均明显强于糖尿病组及糖尿病合并冠心病组(17 318.60±4 364.77比34 171.67±13 918.07及39 633.60±8 728.22,均为P<0.05)。健康对照组HDL抑制VCAM-1表达能力明显强于糖尿病合并冠心病组(244.80±119.55比388.80±75.76,P=0.04)。健康对照组及各疾病组HDL均可抑制THP-1细胞粘附HUVEC的能力,但健康对照组HDL抑制细胞粘附能力明显强于糖尿病组、冠心病组及糖尿病合并冠心病组(503.24±63.50比2 918.00±0.00、1 510.33±1 353.87及4 196.50±412.60,均为P<0.05)。HDL中SAA的含量与其抗ICAM-1表达(回归系数为1.57,t=3.22,P<0.01)及THP-1细胞粘附能力(回归系数为1.16,t=3.05,P=0.01)具有明显相关性。HDL中apo AⅠ的含量与其抗ICAM-1表达能力具有明显相关性(回归系数为-0.35,t=-2.40,P=0.02)。结论糖尿病和冠心病患者HDL抑制血管内皮细胞粘附分子表达及抑制单核细胞粘附能力均显著减弱。SAA含量越多,HDL抑制粘附能力越弱;apo AⅠ含量越高,HDL抑制细胞粘附能力越强。     

In vivo evidence for both lipolytic and nonlipolytic function of hepatic lipase in the metabolism of HDL

To investigate the in vivo role that hepatic lipase (HL) plays in HDL metabolism independently of its lipolytic function, recombinant adenovirus (rAdV) expressing native HL, catalytically inactive HL (HL-145G), and luciferase control was injected in HL-deficient mice. At day 4 after infusion of 2 x 10(8) plaque-forming units of rHL-AdV and rHL-145G-AdV, similar plasma concentrations were detected in postheparin plasma (HL=8.4+/-0.8 microg/mL and HL-145G=8.3+/-0.8 microg/mL). Mice expressing HL had significant reductions of cholesterol (-76%), phospholipids (PL; -68%), HDL cholesterol (-79%), apolipoprotein (apo) A-I (-45%), and apoA-II (-59%; P<0.05 for all), whereas mice expressing HL-145G decreased their cholesterol (-49%), PL (-40%), HDL cholesterol (-42%), and apoA-II (-89%; P<0.005 for all) but had no changes in apoA-I. The plasma kinetics of (125)I-labeled apoA-I HDL, (131)I-labeled apoA-II HDL, and [(3)H]cholesteryl ester (CE) HDL revealed that compared with mice expressing luciferase control (fractional catabolic rate [FCR] in d(-1): apoA-I HDL=1.3+/-0.1; apoA-II HDL=2.1+/-0; CE HDL=4.1+/-0.7), both HL and HL-145G enhanced the plasma clearance of CEs and apoA-II present in HDL (apoA-II HDL=5.6+/-0.5 and 4.4+/-0.2; CE HDL=9.3+/-0. 0 and 8.3+/-1.1, respectively), whereas the clearance of apoA-I HDL was enhanced in mice expressing HL (FCR=4.6+/-0.3) but not HL-145G (FCR=1.4+/-0.4). These combined findings demonstrate that both lipolytic and nonlipolytic functions of HL are important for HDL metabolism in vivo. Our study provides, for the first time, in vivo evidence for a role of HL in HDL metabolism independent of lipolysis and provides new insights into the role of HL in facilitating distinct metabolic pathways involved in the catabolism of apoA-I- versus apoA-II-containing HDL.     

Anti-RhD antibody therapy modulates human natural killer cell function

Anti-RhD antibodies are widely used in clinical practice to prevent immunization against RhD, principally in hemolytic disease of the fetus and newborn. Intriguingly, this disease is induced by production of the very same antibodies when an RhD negative woman is pregnant with an RhD positive fetus. Despite over five decades of use, the mechanism of this treatment is, surprisingly, still unclear. Here we show that anti-RhD antibodies induce human natural killer (NK) cell degranulation. Mechanistically, we demonstrate that NK cell degranulation is mediated by binding of the Fc segment of anti-RhD antibodies to CD16, the main Fcγ receptor expressed on NK cells. We found that this CD16 activation is dependent upon glycosylation of the anti-RhD antibodies. Furthermore, we show that anti-RhD antibodies induce NK cell degranulation in vivo in patients who receive this treatment prophylactically. Finally, we demonstrate that the anti-RhD drug KamRho enhances the killing of dendritic cells. We suggest that this killing leads to reduced activation of adaptive immunity and may therefore affect the production of anti-RhD antibodies     

DNA from probiotic bacteria modulates murine and human epithelial and immune function

BACKGROUND & AIMS: The intestinal epithelium must discriminate between pathogenic and nonpathogenic bacteria and respond accordingly. The aim of this study was to examine whether bacterial DNA can serve as the molecular basis for bacterial recognition. METHODS: HT-29 monolayers were treated with various bacterial DNA and interleukin (IL)-8 secretion measured by enzyme-linked immunosorbent assay, nuclear factor kappaB activation by electrophoretic mobility shift assay and reporter assays, and IkappaB levels by Western blotting. Cytokine secretion in response to bacterial DNA was measured in murine colonic segments and splenocytes. IL-10-deficient mice were fed DNA from VSL probiotic compound daily for 2 weeks. Colons were removed and analyzed for cytokine production and inflammation. RESULTS: HT-29 cells responded with IL-8 secretion to bacterial DNA in a differential manner. In the presence of proinflammatory stimuli, VSL3 DNA inhibited IL-8 secretion, reduced p38 mitogen-activated protein kinase activation, delayed nuclear factor kappaB activation, stabilized levels of IkappaB, and inhibited proteasome function. VSL3 DNA inhibited colonic interferon (IFN)-gamma secretion in mouse colons and also attenuated a Bacteroides vulgatus-induced IFN-gamma release from murine splenocytes. In mice, VSL3 DNA attenuated a systemic release of tumor necrosis factor alpha in response to Escherichia coli DNA injection. Treatment of IL-10-deficient mice with oral VSL3 DNA resulted in a reduction in mucosal secretion of tumor necrosis factor alpha and IFN-gamma and an improvement in histologic disease. CONCLUSIONS: DNA from probiotic bacteria can limit epithelial proinflammatory responses in vivo and in vitro. Systemic and oral administration of VSL3 DNA ameliorates inflammatory responses.     

A secretory function of human insulin-producing cells in vivo

BACKGROUND:Mesenchymal stem cells derived from human umbilical cord blood(UCB-MSCs)have good research and application prospects in the treatment of diabetes.We once induced UCB-MSCs to differentiate into insulin-producing cells(IPCs)in vitro,but we did not know the functions of these cells in vivo.The aim of this study was to assess the functional effects of IPCs on insulin secretion and their role in the treatment of diabetes in vivo. METHODS:UCB-MSCs were induced to IPCs by an inducing protocol with extra...     

Interleukin-3 administration enhances human monocyte function in vivo

Summary. In addition to its haemopoietic effects, interleukin-3 (IL-3) enhances leucocyte function in vitro . In this study we examined the effects on haematological variables and monocyte function of a single IL-3 infusion in five haematologically normal individuals. There was a rapid fall in circulating monocyte (to 24 ± 6% of pre-infusion value) and eosinophil numbers (to 3 ± 2%) with a nadir at 30 min and gradual return to baseline over 6h. No significant changes in monocyte expression of the adhesion molecules CD11b or L-selectin or of monocyte respiratory burst activity were detected. There was a significant increase in monocyte phagocytosis and killing of Canadida after IL-3 infusion: the percentage of monocytes which had ingested Candida increased from 39 ± 10% to 62 ± 12% and the total number of Candida killed per 100 monocytes increased from 63 ± 34 to 210 ± 59 ( P < 0.05 and P < 0.01 respectively). There was no inhibition of neutrophil migration into a 'skin window' site and monocyte migration was moderately enhanced (peak increase of 260 ± 47%). These results show that IL-3 has significant effects on monocyte function in vivo and could be of use in augmenting host defence mechanisms in immunocompromised patients.     

HDL功能检测与冠状动脉斑块的相关性

目的针对正常高密度脂蛋白胆固醇(HDLC)水平(≥1.03 mmol/L)的冠心病患者,分析其血浆高密度脂蛋白(HDL)功能与冠状动脉狭窄及斑块性质的相关性。方法选取2015年10月至2017年12月在宜昌市中医医院接受64排螺旋CT冠状动脉造影(CTA)检查,并具有正常HDLC水平的疑似冠心病患者129例为研究对象,利用CTA检测进行冠状动脉狭窄程度及斑块性质分组,统计分析血浆HDL功能指标对氧磷酶1(PON1)活性及HDL氧化/抗氧化指数与其相关性。结果与非冠心病组比较,冠心病组HDLC水平、PON1活性下降,HDL氧化/抗氧化指数升高,显示为氧化状态,而ApoAI水平没有差异。随着冠状动脉狭窄程度增加,PON1活性逐渐降低,HDL氧化/抗氧化指数逐渐增高,而HDLC水平、ApoAI水平无明显差异。不同斑块性质分组分析显示,钙化斑块组PON1活性高于软斑块组及混合斑块组。PON1活性与HDLC、HDL氧化/抗氧化指数有一定相关性。结论HDL的功能检测中PON1活性对于冠心病的斑块性质及狭窄程度有良好的评价价值。     

Phosphatidylserine exposure on the surface of Leishmania amazonensis amastigotes modulates in vivo infection and dendritic cell function

Leishmania amazonensis parasites can cause diverse forms of leishmaniasis in humans and persistent lesions in most inbred strains of mice. In both cases, the infection is characterized by a marked immunosuppression of the host. We previously showed that amastigote forms of the parasite make use of surface‐exposed phosphatidylserine (PS) molecules to infect host cells and promote alternative macrophage activation, leading to uncontrolled intracellular proliferation of the parasites. In this study, we demonstrated that treatment of infected mice with a PS‐targeting monoclonal antibody ameliorated parasite loads and lesion development, which correlated with increased proliferative responses by lymphocytes. In addition, we observed an enhanced dendritic cell (DC) activation and antigen presentation in vitro. Our data imply that the recognition of PS exposed on the surface of amastigotes plays a role in down‐modulating DC functions, in a matter similar to that of apoptotic cell clearance. This study provides new information regarding the mechanism of immune suppression in Leishmania infection.